generic/zip.cpp

   1 #include "lsnes.hpp"
   2 #include "zip.hpp"
   3 #include <cstdint>
   4 #include <cstring>
   5 #include <iostream>
   6 #include <stdexcept>
   7 #include <boost/iostreams/categories.hpp>
   8 #include <boost/iostreams/copy.hpp>
   9 #include <boost/iostreams/stream.hpp>
  10 #include <boost/iostreams/stream_buffer.hpp>
  11 #include <boost/iostreams/filter/symmetric.hpp>
  12 #include <boost/iostreams/filter/zlib.hpp>
  13 #include <boost/iostreams/filtering_stream.hpp>
  14 #include <boost/iostreams/device/back_inserter.hpp>
  15
  16 namespace
  17 {
  18         uint32_t read32(const unsigned char* buf, unsigned offset = 0, unsigned modulo = 4) throw()
  19         {
  20                 return (uint32_t)buf[offset % modulo] |
  21                         ((uint32_t)buf[(offset + 1) % modulo] << 8) |
  22                         ((uint32_t)buf[(offset + 2) % modulo] << 16) |
  23                         ((uint32_t)buf[(offset + 3) % modulo] << 24);
  24         }
  25
  26         uint16_t read16(const unsigned char* buf) throw()
  27         {
  28                 return (uint16_t)buf[0] | ((uint16_t)buf[1] << 8);
  29         }
  30
  31         void write16(unsigned char* buf, uint16_t value) throw()
  32         {
  33                 buf[0] = (value) & 0xFF;
  34                 buf[1] = (value >> 8) & 0xFF;
  35         }
  36
  37         void write32(unsigned char* buf, uint32_t value) throw()
  38         {
  39                 buf[0] = (value) & 0xFF;
  40                 buf[1] = (value >> 8) & 0xFF;
  41                 buf[2] = (value >> 16) & 0xFF;
  42                 buf[3] = (value >> 24) & 0xFF;
  43         }
  44
  45         class file_input
  46         {
  47         public:
  48                 typedef char char_type;
  49                 typedef boost::iostreams::source_tag category;
  50                 file_input(std::ifstream& _stream, size_t* _refcnt)
  51                         : stream(_stream), stream_refcnt(*_refcnt)
  52                 {
  53                         stream_refcnt++;
  54                         position = stream.tellg();
  55                         left_unlimited = true;
  56                 }
  57
  58                 file_input(std::ifstream& _stream, uint32_t size, size_t* _refcnt)
  59                         : stream(_stream), stream_refcnt(*_refcnt)
  60                 {
  61                         stream_refcnt++;
  62                         position = stream.tellg();
  63                         left_unlimited = false;
  64                         left = size;
  65                 }
  66
  67                 void close()
  68                 {
  69                 }
  70
  71                 std::streamsize read(char* s, std::streamsize n)
  72                 {
  73                         stream.clear();
  74                         stream.seekg(position, std::ios_base::beg);
  75                         if(stream.fail())
  76                                 throw std::runtime_error("Can't seek ZIP file");
  77                         if(!left_unlimited && left == 0)
  78                                 return -1;
  79                         if(!left_unlimited && n > left)
  80                                 n = left;
  81                         stream.read(s, n);
  82                         std::streamsize r = stream.gcount();
  83                         if(r == 0 && stream.fail())
  84                                 throw std::runtime_error("Can't read compressed data from ZIP file");
  85                         if(!stream && r == 0)
  86                                 return -1;
  87                         position += r;
  88                         left -= r;
  89                         return r;
  90                 }
  91
  92                 ~file_input()
  93                 {
  94                         if(!--stream_refcnt) {
  95                                 delete &stream;
  96                                 delete &stream_refcnt;
  97                         }
  98                 }
  99
 100                 file_input(const file_input& f)
 101                         : stream(f.stream), stream_refcnt(f.stream_refcnt)
 102                 {
 103                         stream_refcnt++;
 104                         position = f.position;
 105                         left_unlimited = f.left_unlimited;
 106                         left = f.left;
 107                 }
 108         protected:
 109                 std::ifstream& stream;
 110                 size_t& stream_refcnt;
 111                 std::streamoff position;
 112                 bool left_unlimited;
 113                 uint32_t left;
 114         private:
 115                 file_input& operator=(const file_input& f);
 116         };
 117
 118         class vector_output
 119         {
 120         public:
 121                 typedef char char_type;
 122                 typedef boost::iostreams::sink_tag category;
 123                 vector_output(std::vector<char>& _stream)
 124                         : stream(_stream)
 125                 {
 126                 }
 127
 128                 void close()
 129                 {
 130                 }
 131
 132                 std::streamsize write(const char* s, std::streamsize n)
 133                 {
 134                         size_t oldsize = stream.size();
 135                         stream.resize(oldsize + n);
 136                         memcpy(&stream[oldsize], s, n);
 137                         return n;
 138                 }
 139         protected:
 140                 std::vector<char>& stream;
 141         };
 142
 143         class size_and_crc_filter_impl
 144         {
 145         public:
 146                 typedef char char_type;
 147
 148                 size_and_crc_filter_impl()
 149                 {
 150                         dsize = 0;
 151                         crc = ::crc32(0, NULL, 0);
 152                 }
 153
 154                 void close()
 155                 {
 156                 }
 157
 158                 bool filter(const char*& src_begin, const char* src_end, char*& dest_begin, char* dest_end,
 159                         bool flush)
 160                 {
 161                         ptrdiff_t amount = src_end - src_begin;
 162                         if(flush && amount == 0)
 163                                 return false;
 164                         if(amount > dest_end - dest_begin)
 165                                 amount = dest_end - dest_begin;
 166                         dsize += amount;
 167                         crc = ::crc32(crc, reinterpret_cast<const unsigned char*>(src_begin), amount);
 168                         memcpy(dest_begin, src_begin, amount);
 169                         src_begin += amount;
 170                         dest_begin += amount;
 171                         return true;
 172                 }
 173
 174                 uint32_t size()
 175                 {
 176                         return dsize;
 177                 }
 178
 179                 uint32_t crc32()
 180                 {
 181                         return crc;
 182                 }
 183         private:
 184                 uint32_t dsize;
 185                 uint32_t crc;
 186         };
 187
 188         class size_and_crc_filter : public boost::iostreams::symmetric_filter<size_and_crc_filter_impl,
 189                 std::allocator<char>>
 190         {
 191                 typedef symmetric_filter<size_and_crc_filter_impl, std::allocator<char>> base_type;
 192         public:
 193                 typedef typename base_type::char_type char_type;
 194                 typedef typename base_type::category category;
 195                 size_and_crc_filter(int bsize)
 196                         : base_type(bsize)
 197                 {
 198                 }
 199
 200                 uint32_t size()
 201                 {
 202                         return filter().size();
 203                 }
 204
 205                 uint32_t crc32()
 206                 {
 207                         return filter().crc32();
 208                 }
 209         };
 210
 211         struct zipfile_member_info
 212         {
 213                 bool central_directory_special; //Central directory, not real member.
 214                 uint16_t version_needed;
 215                 uint16_t flags;
 216                 uint16_t compression;
 217                 uint16_t mtime_time;
 218                 uint16_t mtime_day;
 219                 uint32_t crc;
 220                 uint32_t compressed_size;
 221                 uint32_t uncompressed_size;
 222                 std::string filename;
 223                 uint32_t header_offset;
 224                 uint32_t data_offset;
 225                 uint32_t next_offset;
 226         };
 227
 228         //Parse member starting from current offset.
 229         zipfile_member_info parse_member(std::ifstream& file)
 230         {
 231                 zipfile_member_info info;
 232                 info.central_directory_special = false;
 233                 info.header_offset = file.tellg();
 234                 //The file header is 30 bytes (this could also hit central header, but that's even larger).
 235                 unsigned char buffer[30];
 236                 if(!(file.read(reinterpret_cast<char*>(buffer), 30)))
 237                         throw std::runtime_error("Can't read file header from ZIP file");
 238                 uint32_t magic = read32(buffer);
 239                 if(magic == 0x02014b50) {
 240                         info.central_directory_special = true;
 241                         return info;
 242                 }
 243                 if(magic != 0x04034b50)
 244                         throw std::runtime_error("ZIP archive corrupt: Expected file or central directory magic");
 245                 info.version_needed = read16(buffer + 4);
 246                 info.flags = read16(buffer + 6);
 247                 info.compression = read16(buffer + 8);
 248                 info.mtime_time = read16(buffer + 10);
 249                 info.mtime_day = read16(buffer + 12);
 250                 info.crc = read32(buffer + 14);
 251                 info.compressed_size = read32(buffer + 18);
 252                 info.uncompressed_size = read32(buffer + 22);
 253                 uint16_t filename_len = read16(buffer + 26);
 254                 uint16_t extra_len = read16(buffer + 28);
 255                 if(!filename_len)
 256                         throw std::runtime_error("Unsupported ZIP feature: Empty filename not allowed");
 257                 if(info.version_needed > 20) {
 258                         throw std::runtime_error("Unsupported ZIP feature: Only ZIP versions up to 2.0 supported");
 259                 }
 260                 if(info.flags & 0x2001)
 261                         throw std::runtime_error("Unsupported ZIP feature: Encryption is not supported");
 262                 if(info.flags & 0x8)
 263                         throw std::runtime_error("Unsupported ZIP feature: Indeterminate length not supported");
 264                 if(info.flags & 0x20)
 265                         throw std::runtime_error("Unsupported ZIP feature: Binary patching is not supported");
 266                 if(info.compression != 0 && info.compression != 8)
 267                         throw std::runtime_error("Unsupported ZIP feature: Unsupported compression method");
 268                 if(info.compression == 0 && info.compressed_size != info.uncompressed_size)
 269                         throw std::runtime_error("ZIP archive corrupt: csize ≠ usize for stored member");
 270                 std::vector<unsigned char> filename_storage;
 271                 filename_storage.resize(filename_len);
 272                 if(!(file.read(reinterpret_cast<char*>(&filename_storage[0]), filename_len)))
 273                         throw std::runtime_error("Can't read file name from zip file");
 274                 info.filename = std::string(reinterpret_cast<char*>(&filename_storage[0]), filename_len);
 275                 info.data_offset = info.header_offset + 30 + filename_len + extra_len;
 276                 info.next_offset = info.data_offset + info.compressed_size;
 277                 return info;
 278         }
 279 }
 280
 281 bool zip_reader::has_member(const std::string& name) throw()
 282 {
 283         return (offsets.count(name) > 0);
 284 }
 285
 286 std::string zip_reader::find_first() throw(std::bad_alloc)
 287 {
 288         if(offsets.empty())
 289                 return "";
 290         else
 291                 return offsets.begin()->first;
 292 }
 293
 294 std::string zip_reader::find_next(const std::string& name) throw(std::bad_alloc)
 295 {
 296         auto i = offsets.upper_bound(name);
 297         if(i == offsets.end())
 298                 return "";
 299         else
 300                 return i->first;
 301 }
 302
 303 std::istream& zip_reader::operator[](const std::string& name) throw(std::bad_alloc, std::runtime_error)
 304 {
 305         if(!offsets.count(name))
 306                 throw std::runtime_error("No such file '" + name + "' in zip archive");
 307         zipstream->clear();
 308         zipstream->seekg(offsets[name], std::ios::beg);
 309         zipfile_member_info info = parse_member(*zipstream);
 310         zipstream->clear();
 311         zipstream->seekg(info.data_offset, std::ios::beg);
 312         if(info.compression == 0) {
 313                 return *new boost::iostreams::stream<file_input>(*zipstream, info.uncompressed_size, refcnt);
 314         } else if(info.compression == 8) {
 315                 boost::iostreams::filtering_istream* s = new boost::iostreams::filtering_istream();
 316                 boost::iostreams::zlib_params params;
 317                 params.noheader = true;
 318                 s->push(boost::iostreams::zlib_decompressor(params));
 319                 s->push(file_input(*zipstream, info.compressed_size, refcnt));
 320                 return *s;
 321         } else
 322                 throw std::runtime_error("Unsupported ZIP feature: Unsupported compression method");
 323 }
 324
 325 zip_reader::iterator zip_reader::begin() throw(std::bad_alloc)
 326 {
 327         return iterator(offsets.begin());
 328 }
 329
 330 zip_reader::iterator zip_reader::end() throw(std::bad_alloc)
 331 {
 332         return iterator(offsets.end());
 333 }
 334
 335 zip_reader::riterator zip_reader::rbegin() throw(std::bad_alloc)
 336 {
 337         return riterator(offsets.rbegin());
 338 }
 339
 340 zip_reader::riterator zip_reader::rend() throw(std::bad_alloc)
 341 {
 342         return riterator(offsets.rend());
 343 }
 344
 345 zip_reader::~zip_reader() throw()
 346 {
 347         if(!--*refcnt) {
 348                 delete zipstream;
 349                 delete refcnt;
 350         }
 351 }
 352
 353 zip_reader::zip_reader(const std::string& zipfile) throw(std::bad_alloc, std::runtime_error)
 354 {
 355         zipfile_member_info info;
 356         info.next_offset = 0;
 357         zipstream = new std::ifstream;
 358         zipstream->open(zipfile.c_str(), std::ios::binary);
 359         refcnt = new size_t;
 360         *refcnt = 1;
 361         if(!*zipstream)
 362                 throw std::runtime_error("Can't open zipfile '" + zipfile + "' for reading");
 363         do {
 364                 zipstream->clear();
 365                 zipstream->seekg(info.next_offset);
 366                 if(zipstream->fail())
 367                         throw std::runtime_error("Can't seek ZIP file");
 368                 info = parse_member(*zipstream);
 369                 if(info.central_directory_special)
 370                         break;
 371                 offsets[info.filename] = info.header_offset;
 372         } while(1);
 373 }
 374
 375 zip_writer::zip_writer(const std::string& zipfile, unsigned _compression) throw(std::bad_alloc, std::runtime_error)
 376 {
 377         compression = _compression;
 378         zipfile_path = zipfile;
 379         temp_path = zipfile + ".tmp";
 380         zipstream.open(temp_path.c_str(), std::ios::binary);
 381         if(!zipstream)
 382                 throw std::runtime_error("Can't open zipfile '" + temp_path + "' for writing");
 383         committed = false;
 384 }
 385
 386 zip_writer::~zip_writer() throw()
 387 {
 388         if(!committed)
 389                 remove(temp_path.c_str());
 390 }
 391
 392 void zip_writer::commit() throw(std::bad_alloc, std::logic_error, std::runtime_error)
 393 {
 394         if(committed)
 395                 throw std::logic_error("Can't commit twice");
 396         if(open_file != "")
 397                 throw std::logic_error("Can't commit with file open");
 398         std::vector<unsigned char> directory_entry;
 399         uint32_t cdirsize = 0;
 400         uint32_t cdiroff = zipstream.tellp();
 401         if(cdiroff == (uint32_t)-1)
 402                 throw std::runtime_error("Can't read current ZIP stream position");
 403         for(auto i : files) {
 404                 cdirsize += (46 + i.first.length());
 405                 directory_entry.resize(46 + i.first.length());
 406                 write32(&directory_entry[0], 0x02014b50);
 407                 write16(&directory_entry[4], 3);
 408                 write16(&directory_entry[6], 20);
 409                 write16(&directory_entry[8], 8);
 410                 write16(&directory_entry[10], compression ? 8 : 0);
 411                 write16(&directory_entry[12], 0);
 412                 write16(&directory_entry[14], 10273);
 413                 write32(&directory_entry[16], i.second.crc);
 414                 write32(&directory_entry[20], i.second.compressed_size);
 415                 write32(&directory_entry[24], i.second.uncompressed_size);
 416                 write16(&directory_entry[28], i.first.length());
 417                 write16(&directory_entry[30], 0);
 418                 write16(&directory_entry[32], 0);
 419                 write16(&directory_entry[34], 0);
 420                 write16(&directory_entry[36], 0);
 421                 write32(&directory_entry[38], 0);
 422                 write32(&directory_entry[42], i.second.offset);
 423                 memcpy(&directory_entry[46], i.first.c_str(), i.first.length());
 424                 zipstream.write(reinterpret_cast<char*>(&directory_entry[0]), directory_entry.size());
 425                 if(!zipstream)
 426                         throw std::runtime_error("Failed to write central directory entry to output file");
 427         }
 428         directory_entry.resize(22);
 429         write32(&directory_entry[0], 0x06054b50);
 430         write16(&directory_entry[4], 0);
 431         write16(&directory_entry[6], 0);
 432         write16(&directory_entry[8], files.size());
 433         write16(&directory_entry[10], files.size());
 434         write32(&directory_entry[12], cdirsize);
 435         write32(&directory_entry[16], cdiroff);
 436         write16(&directory_entry[20], 0);
 437         zipstream.write(reinterpret_cast<char*>(&directory_entry[0]), directory_entry.size());
 438         if(!zipstream)
 439                 throw std::runtime_error("Failed to write central directory end marker to output file");
 440         zipstream.close();
 441         std::string backup = zipfile_path + ".backup";
 442 #if defined(_WIN32) || defined(_WIN64) || defined(TEST_WIN32_CODE)
 443         //Grumble, Windows seemingly can't do this atomically.
 444         remove(backup.c_str());
 445 #endif
 446         rename(zipfile_path.c_str(), backup.c_str());
 447         if(rename(temp_path.c_str(), zipfile_path.c_str()) < 0)
 448                 throw std::runtime_error("Can't rename '" + temp_path + "' -> '" + zipfile_path + "'");
 449         committed = true;
 450 }
 451
 452 std::ostream& zip_writer::create_file(const std::string& name) throw(std::bad_alloc, std::logic_error,
 453         std::runtime_error)
 454 {
 455         if(open_file != "")
 456                 throw std::logic_error("Can't open file with file open");
 457         if(name == "")
 458                 throw std::runtime_error("Bad member name");
 459         current_compressed_file.resize(0);
 460         s = new boost::iostreams::filtering_ostream();
 461         s->push(size_and_crc_filter(4096));
 462         if(compression) {
 463                 boost::iostreams::zlib_params params;
 464                 params.noheader = true;
 465                 s->push(boost::iostreams::zlib_compressor(params));
 466         }
 467         s->push(vector_output(current_compressed_file));
 468         open_file = name;
 469         return *s;
 470 }
 471
 472 void zip_writer::close_file() throw(std::bad_alloc, std::logic_error, std::runtime_error)
 473 {
 474         if(open_file == "")
 475                 throw std::logic_error("Can't close file with no file open");
 476         uint32_t ucs, cs, crc32;
 477         boost::iostreams::close(*s);
 478         size_and_crc_filter& f = *s->component<size_and_crc_filter>(0);
 479         cs = current_compressed_file.size();
 480         ucs = f.size();
 481         crc32 = f.crc32();
 482         delete s;
 483
 484         base_offset = zipstream.tellp();
 485         if(base_offset == (uint32_t)-1)
 486                 throw std::runtime_error("Can't read current ZIP stream position");
 487         unsigned char header[30];
 488         memset(header, 0, 30);
 489         write32(header, 0x04034b50);
 490         header[4] = 20;
 491         header[6] = 0;
 492         header[8] = compression ? 8 : 0;
 493         header[12] = 33;
 494         header[13] = 40;
 495         write32(header + 14, crc32);
 496         write32(header + 18, cs);
 497         write32(header + 22, ucs);
 498         write16(header + 26, open_file.length());
 499         zipstream.write(reinterpret_cast<char*>(header), 30);
 500         zipstream.write(open_file.c_str(), open_file.length());
 501         zipstream.write(&current_compressed_file[0], current_compressed_file.size());
 502         if(!zipstream)
 503                 throw std::runtime_error("Can't write member to ZIP file");
 504         current_compressed_file.resize(0);
 505         zip_file_info info;
 506         info.crc = crc32;
 507         info.uncompressed_size = ucs;
 508         info.compressed_size = cs;
 509         info.offset = base_offset;
 510         files[open_file] = info;
 511         open_file = "";
 512 }
 513
 514 namespace
 515 {
 516 #if defined(_WIN32) || defined(_WIN64) || defined(TEST_WIN32_CODE)
 517         const char* path_splitters = "\\/";
 518         bool drives_allowed = true;
 519 #else
 520         //Assume Unix(-like) system.
 521         const char* path_splitters = "/";
 522         bool drives_allowed = false;
 523 #endif
 524
 525         const char* str_index(const char* str, int ch)
 526         {
 527                 while(*str)
 528                         if(*str == ch)
 529                                 return str;
 530                 return NULL;
 531         }
 532
 533         bool ispathsep(char ch)
 534         {
 535                 return (str_index(path_splitters, static_cast<int>(static_cast<unsigned char>(ch))) != NULL);
 536         }
 537
 538         bool isroot(const std::string& path)
 539         {
 540                 if(path.length() == 1 && ispathsep(path[0]))
 541                         return true;
 542                 if(!drives_allowed)
 543                         //NO more cases for this.
 544                         return false;
 545                 if(path.length() == 3 && path[0] >= 'A' && path[0] <= 'Z' && path[1] == ':' && ispathsep(path[2]))
 546                         return true;
 547                 //UNC.
 548                 if(path.length() <= 3 || !ispathsep(path[0]) || !ispathsep(path[1]) ||
 549                         !ispathsep(path[path.length() - 1]))
 550                         return false;
 551                 return (path.find_first_of(path_splitters, 2) == path.length() - 1);
 552         }
 553
 554         std::string walk(const std::string& path, const std::string& component)
 555         {
 556                 if(component == "" || component == ".")
 557                         //Current directory.
 558                         return path;
 559                 else if(component == "..") {
 560                         //Parent directory.
 561                         if(path == "" || isroot(path))
 562                                 throw std::runtime_error("Can't rise to containing directory");
 563                         std::string _path = path;
 564                         size_t split = _path.find_last_of(path_splitters);
 565                         if(split < _path.length())
 566                                 return _path.substr(0, split);
 567                         else
 568                                 return "";
 569                 } else if(path == "" || ispathsep(path[path.length() - 1]))
 570                         return path + component;
 571                 else
 572                         return path + "/" + component;
 573         }
 574
 575         std::string combine_path(const std::string& _name, const std::string& _referencing_path)
 576         {
 577                 std::string name = _name;
 578                 std::string referencing_path = _referencing_path;
 579                 size_t x = referencing_path.find_last_of(path_splitters);
 580                 if(x < referencing_path.length())
 581                         referencing_path = referencing_path.substr(0, x);
 582                 else
 583                         return name;
 584                 //Check if name is absolute.
 585                 if(ispathsep(name[0]))
 586                         return name;
 587                 if(drives_allowed && name.length() >= 3 && name[0] >= 'A' && name[0] <= 'Z' && name[1] == ':' &&
 588                         ispathsep(name[2]))
 589                         return name;
 590                 //It is not absolute.
 591                 std::string path = referencing_path;
 592                 size_t pindex = 0;
 593                 while(true) {
 594                         size_t split = name.find_first_of(path_splitters, pindex);
 595                         std::string c;
 596                         if(split < name.length())
 597                                 c = name.substr(pindex, split - pindex);
 598                         else
 599                                 c = name.substr(pindex);
 600                         path = walk(path, c);
 601                         if(split < name.length())
 602                                 pindex = split + 1;
 603                         else
 604                                 break;
 605                 }
 606                 //If path becomes empty, assume it means current directory.
 607                 if(path == "")
 608                         path = ".";
 609                 return path;
 610         }
 611 }
 612
 613 std::string resolve_file_relative(const std::string& name, const std::string& referencing_path) throw(std::bad_alloc,
 614         std::runtime_error)
 615 {
 616         return combine_path(name, referencing_path);
 617 }
 618
 619 std::istream& open_file_relative(const std::string& name, const std::string& referencing_path) throw(std::bad_alloc,
 620         std::runtime_error)
 621 {
 622         std::string path_to_open = combine_path(name, referencing_path);
 623         std::string final_path = path_to_open;
 624         //Try to open this from the main OS filesystem.
 625         std::ifstream* i = new std::ifstream(path_to_open.c_str(), std::ios::binary);
 626         if(i->is_open()) {
 627                 return *i;
 628         }
 629         delete i;
 630         //Didn't succeed. Try to open as ZIP archive.
 631         std::string membername;
 632         while(true) {
 633                 size_t split = path_to_open.find_last_of("/");
 634                 if(split >= path_to_open.length())
 635                         throw std::runtime_error("Can't open '" + final_path + "'");
 636                 //Move a component to member name.
 637                 if(membername != "")
 638                         membername = path_to_open.substr(split + 1) + "/" + membername;
 639                 else
 640                         membername = path_to_open.substr(split + 1);
 641                 path_to_open = path_to_open.substr(0, split);
 642                 try {
 643                         zip_reader r(path_to_open);
 644                         return r[membername];
 645                 } catch(std::bad_alloc& e) {
 646                         throw;
 647                 } catch(std::runtime_error& e) {
 648                 }
 649         }
 650 }
 651
 652 std::vector<char> read_file_relative(const std::string& name, const std::string& referencing_path) throw(std::bad_alloc,
 653         std::runtime_error)
 654 {
 655         std::vector<char> out;
 656         std::istream& s = open_file_relative(name, referencing_path);
 657         boost::iostreams::back_insert_device<std::vector<char>> rd(out);
 658         boost::iostreams::copy(s, rd);
 659         delete &s;
 660         return out;
 661 }